At present several laser treatment apparatuses are used to realize industrial applications of lasers for such production processes as thermal surface hardening, doping, welding, cutting, and other types of working of pieces varying in their size, shape, and material.
Known in the art is an apparatus for laser treatment of materials (FR, B, 2492703; or similar GB, A, 2088267), which can be used to cut metal sheets. This apparatus comprises a laser, a coordinate table on which the material to be treated is placed, a system for delivery, transformation, and focusing laser radiation, equipped with an output barrel, which is arranged along the laser beam. The apparatus is also provided with a numerical control (NC) system connected to the laser and coordinate table.
In this prior art apparatus for laser treatment of materials the laser beam is focused by a lens incorporated into the laser radiation delivery, transformation and focusing system and is directed, through a small-diameter nozzle of the output barrel, to the material to be treated. Simultaneously gas for cutting is supplied through the nozzle of the barrel coaxially with the laser beam. The sheet material is secured on the coordinate table which is controlled by the NC system. The sheet, together with the table, is transported along a desired path and cut by the laser beam.
Limitations of this laser treatment apparatus and similar devices are obvious-they can only be used for contour cutting of sheet materials.
The apparatus for laser treatment of materials (DE, C, 3217226) is equipped with a laser radiation delivery, transformation and focusing system comprising a shell connected to a rotation drive, the axis of rotation coincides with the axis of the laser beam. This system also comprises three mirrors arranged in the shell so that normals to the surfaces thereof lie in one plane with the axis of rotation of the shell, the normal to the surface of the second mirror is perpendicular to the shell axis of rotation, while normals to the surfaces of the first and third mirrors make acute angles with the normal to the surface of the second mirror. Fourth and fifth mirrors are arranged outside the shell and are connected with laser beam scanners in perpendicular planes.
When the drive operates, the shell rotates, and the laser beam coming out of the shell also rotates about its axis. This makes it possible to average irregularities of the laser mode structure and to obtain a sufficiently uniform axially symmetric laser beam. This laser beam is further on directed by the scanning devices of the fourth and fifth mirrors to produce, on the material being treated, a uniformly heated area whose shape is close to rectangular.
This apparatus for laser treatment of materials is deficient in that it contains too many optical components and its design is too complex. It cannot provide a wide range of laser-initiated heat sources of various shapes on the surface of the material being treated. Moreover, this apparatus features stationary scanning planes and the angular orientation of the heat source on the surface of the treated material cannot be changed. To summarize, the apparatus is not versatile and its applications are limited.
Also known in the art is a laser treatment device (FR, B, 2537029) comprising a laser, a coordinate table, a material for treatment, a laser radiation delivery, transformation and focusing system featuring an outlet barrel, which is arranged along the path of the laser beam and equipped with an NC system connected to the laser and the coordinate table, this coordinate table being an industrial robot adapted for rotation on a support. The laser radiation delivery, transportation and focusing system is a rotating work head comprising a laser beam focusing device and a hinged mirror beam guide for delivering laser radiation.
The apparatus operates as follows. The industrial robot positions the work head equipped with a hinged mirror beam guide in accordance with the program of the numerical control system. The material can be subjected to laser cutting or welding along an elaborate path.
But the apparatus described above is not universally applicable, the range of production operations and their types are limited because the apparatus uses only one work head and the structure of laser radiation hitting the material being treated cannot be either modified or changed altogether during the operational cycle.